i = int(input())
if i >= 30:
    print('Yes')
else:
    print('No') i = int(input()) i int(input()) int input() input if i >= 30:
    print('Yes')
else:
    print('No') i >= 30 i 30 print('Yes') print 'Yes' print('No') print 'No' i = int(input()) int(input()) i
i = int(input())
if i >= 30:
    print('Yes')
else:
    print('No')